In the manufacture of integrated circuits and other semiconductor devices, the sequence of processing operations used to fabricate the devices on a substrate typically includes a number of heat treatment operations. The heat treatment operations include annealing operations, such as may be used following an ion implantation operation, silicidation heat treatment operations and other heat treatment operations used to modify properties of materials or structures of the bulk substrate itself or of material and devices formed on the substrate.
Post-implant annealing operations are carried out after ion implantation to activate implanted dopants and to repair implantation damage. Post-implant annealing is advantageously carried out using a thermal budget control, i.e. high temperature for a milli-second time, to avoid dopant diffusion. For this and other reasons, rapid thermal annealing, RTA, flash, and other rapid thermal processing, RTP operations, have become the favored heat treatment operations, as opposed to furnace operations, as semiconductor device processing technology continues to develop.
RTP and RTA utilize a number of individual relatively small-sized high intensity heat lamps that collectively flash at a high intensity for a short time to heat a substrate at a very high temperature with a short time. The heat lamps are generally positioned in close proximity to the substrate undergoing the heat treatment operation and therefore each heat lamp heats a corresponding proximate area of the substrate, so non-uniformities between the lamps result in uneven heating. Semiconductor devices are now being manufactured on substrates that can be 300 mm or 450 mm in diameter and this requires higher numbers of heat lamps and non-uniformities among the heat lamps can produce dramatic heating differences across the substrate surface. This results in material qualities that are inconsistent throughout the substrate and adversely affects device performance and functionality.
One objective that is always present in the semiconductor manufacturing industry is achieving a rapid cycle time. It is highly desirable and most cost-efficient to produce as many devices in a lot, i.e. a group of substrates, as quickly as possible. It is therefore critical to be able to process each substrate as quickly as possible and also to process as many substrates together as possible in various processing operations and apparatuses.
Heat treatment operations that provide uniformity of heating across a substrate and programmable thermal budget control of processing substrates are needed.